1. Field of the Invention
The present invention relates to a process for making silicon nitride whiskers.
2. Description of Related Art
Japanese Patent No. 838,421 discloses a method for making silicon nitride whiskers by mixing amorphous silica powders, to which fluoride, acidic fluoride or silica-fluoride are attached, with carbonaceous powders so as to produce a mixture and heating the mixture in a nitrogen atmosphere at a temperature of 1,300.degree. C. to 1,600.degree. C.
In the conventional process for preparing silicon nitride whiskers, silica powders are mixed with the carbon powders in a solid-solid reaction manner. If they are not properly mixed, no uniform reaction takes place. As a result, diameters of the produced whiskers vary. Even silicon powders are sometimes are produced in admixture with the whiskers.